AT88SC0808CA-WI ATMEL [ATMEL Corporation], AT88SC0808CA-WI Datasheet - Page 3

• Manufacturer Part Number: AT88SC0808CA-WI
• Description: CryptoMemory
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 4-1.
5. Pin Descriptions
5.1
5.2
5.3
5.4
5204AS–CRYPT–7/08
Supply Voltage (VCC)
Clock (SCL/CLK)
Reset (RST)
Serial Data (SDA/IO)
SCL/CLK
Block Diagram
SDA/IO
GND
VCC
RST
The VCC input is a 2.7V to 3.6V positive voltage supplied by the host.
When using the asynchronous T = 0 protocol, the CLK (SCL) input provides the device with a
carrier frequency f. The nominal length of one bit emitted on I/O is defined as an “elementary
time unit” (ETU) and is equal to 372/f.
When using the synchronous protocol, data clocking is done on the positive edge of the clock
when writing to the device and on the negative edge of the clock when reading from the device.
The AT88SC0808CA provides an ISO 7816-3 compliant asynchronous Answer-To-Reset (ATR)
sequence. Upon activation of the reset sequence, the device outputs bytes contained in the 64-
bit Answer-To-Reset register. An internal pull-up on the RST input pad allows the device to oper-
ate in synchronous mode without bonding RST. The AT88SC0808CA does not support an
Answer-To-Reset sequence in the synchronous mode of operation.
The SDA/IO pin is bidirectional for serial data transfer. This pin is open-drain driven and may be
wired with any number of other open-drain or open-collector devices. An external pull-up resistor
should be connected between SDA/IO and VCC. The value of this resistor and the system
capacitance loading the SDA/IO bus will determine the rise time of SDA/IO. This rise time will
determine the maximum frequency during read operations. Low value pull-up resistors will allow
higher frequency operations while drawing higher average power supply current. SDA/IO infor-
mation applies to both asynchronous and synchronous protocols.
Asynchronous
Management
Synchronous
ISO Interface
Reset Block
Interface
Power
Certification Unit
Answer to Reset
Encryption and
Authentication,
Data Transfer
Verification
Password
AT88SC0808CA
Generator
EEPROM
Random
3